Several previous studies support this finding including the large pooled analysis where mutation prevalence decreased with increasing age at diagnosis [ 9, 10, 15, 24- 26].
Most studies that examined p53 mutational spectra found a difference in spectrum by exposure status, despite null or inverse associations with p53 mutation prevalence, possibly because associations with specific mutation patterns were washed out when all mutations were combined into a single case subgroup.
The overall K-Ras mutation prevalence in patients with NSCLC is approximately 16% (or 18% among Caucasian populations), based on two recent meta-analyses of 22 studies with 1470 NSCLC patients treated with EGFR-TKIs [17], [18].
At HFE the A allele at rs1800562 (Cys262Tyr), which is responsible for hereditary hemochromatosis (MIM 235200), was associated with lower levels of HbA1c, rather than the higher levels one would predict from epidemiologic observations of the increased HFE mutation prevalence in patients with type 2 diabetes [ 43, 44].
Only genes with mutation prevalence ≥5% were included to allow sufficient representation of patients with CRC in signature-positive and signature-negative groups.
However, somatic mutation prevalence did correlate significantly with microsatellite length.
PIK3CA contains a total of five domains, so we compared the domain peaks identified by our method to the domains identified with high mutation prevalence, a measure commonly applied to identify genes mutated in a high percentage of patients.
Besides genes of 5q22.2 and 18q21.1-q21.2 described above, we also investigated genes with high mutation prevalence (i.e., P53, KRAS, and PIK3CA), as well as those with intermediate-low mutation prevalence (i.e., SMAD2 and SMAD3) in human CRC [ 46].
Several demographic and pathological factors are associated with EGFR mutation prevalence.
